HARQ-ACK handling for unintended downlink sub-frames

ABSTRACT

Disclosed in some examples is a method for providing a HARQ response in an LTE network for a PUCCH format 1b. The method includes receiving one or more downlink assignments of a bundling window over a wireless downlink control channel; setting a reception status for each sub-frame of a downlink data channel in the bundling window based on whether the sub-frame on the downlink data channel was associated with a particular one of the received downlink assignments and based upon whether the sub-frame was successfully received; setting a reception status of sub-frames of the downlink data channel in the bundling window that did not have a corresponding downlink assignment to a predetermined value; and transmitting a response, the response based upon the reception statuses set by the response module.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.14/605,311, filed on Jan. 26, 2015, now Issued as U.S. Pat. No.9,106,420, which is a continuation of U.S. patent application Ser. No.13/721,458, filed Dec. 20, 2012, issued on Feb. 17, 2015 as U.S. Pat.No. 8,958,331, which claims priority under 35 USC 119 to U.S.Provisional Patent Application Ser. No. 61/667,325, filed Jul. 2, 2012,which is hereby incorporated herein by reference in its entirety.

BACKGROUND

Long Term Evolution (LTE) and other wireless networks rely ontransmission of messages across an unreliable medium between a mobiledevice (e.g., a User Equipment (UE)) and the Radio Access Network (RAN).In LTE the RAN consists of one or more eNodeBs. This unreliablecommunication medium can create problems for proper communication ofdata between the RAN and the UE as data may be lost or corrupted due tolow signal quality, interference, or other problems with the wirelessmedium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table showing mappings from HARQ-ACK responses to resources,constellations and RM Code Input Bits for two cells with a bundlingwindow of 3 according to some examples of the present disclosure.

FIG. 2 is a table showing mappings from HARQ-ACK responses to resources,constellations and RM Code Input Bits for two cells with a bundlingwindow of 4 according to some examples of the present disclosure.

FIG. 2A is a continuation of the table of FIG. 2 according to someexamples of the present disclosure.

FIG. 3 shows a diagram of an example resource allocation according tosome examples of the present disclosure.

FIG. 4 shows a diagram of an example resource allocation according tosome examples of the present disclosure.

FIG. 5A shows a flowchart of a method of generating a HARQ-ACK responseaccording to some examples of the present disclosure.

FIG. 5B shows a flowchart of a method of processing a HARQ-ACK responseaccording to some examples of the present disclosure.

FIG. 6 shows a block diagram of a wireless communication systemaccording to some examples of the present disclosure.

FIG. 7 shows a block functional diagram showing certain functions of aUE and an eNodeB according to some examples of the present disclosure.

FIG. 8 shows a block diagram of a machine according to some examples ofthe present disclosure.

DETAILED DESCRIPTION

In order to deal with the unreliable wireless communication medium, LTEand other cellular networks employ a mechanism called Hybrid AutomaticRepeat Request (HARQ) to provide error correction and packetacknowledgements to ensure the safe delivery of data between the RAN andthe UE. HARQ provides for error correction at the receiver side usingforward error correction coding (FEC) as well as automatic feedbackmechanisms (Automatic Repeat Request (ARQ)) to indicate to the senderwhether or not the packets were successfully received. Upon receipt of apacket of data, the receiver uses an error detection code (e.g., aCyclic Redundancy Check (CRC)) to determine if the packet was correctlyreceived. If the packet was received successfully, the receiveracknowledges the sender using a feedback mechanism (e.g., ACK). If thepacket was not received successfully, the receiver may attempt to repairthe packet using the FEC information. If the receiver is successful inusing the FEC information to repair the packet, it may ACK the sender,otherwise the receiver may respond to the sender with a NegativeAcknowledgement (NACK). In yet other examples, the receiver (the UE) mayrespond that it was in Discontinuous Transmission Mode (DTX) mode. TheDTX response may represent a case in which the UE is not able toproperly detect information on a control channel (e.g., the PrimaryDownlink Control Channel—PDCCH) and thus was unable to determine if apacket was sent to the UE.

In a cellular network, these HARQ responses typically are transmitted onthe control channels. Responses for downlink traffic sent from the RANto the UE are typically sent in uplink control channels (e.g., thePhysical Uplink Control Channel (PUCCH)). Responses for uplink trafficsent from the UE to the RAN are typically sent in downlink HARQ-ACKchannels (e.g., the Physical hybrid HARQ indicator channel: PHICH).Packets that are not acknowledged (either NACKed or simply notacknowledged at all) may be retransmitted by the sender.

In some systems, uplink communications (from the UE to the RAN) areseparated from downlink communications in the frequency domain. That is,the uplink and downlink wireless communications occur on differentfrequency bands. These systems are referred to as Frequency DuplexDivision (FDD) systems. In other examples, the uplink and downlinkwireless communications may share the same frequency bands, but may bedivided in the time domain. That is, the frequency bands are reservedfor the uplink wireless transmissions in some time instances (e.g.called time slots), and the downlink wireless communications in othertime instances (e.g. time slots). This scheme is called Time DivisionDuplex (TDD). In still other examples, half-duplex FDD (H-FDD) systemsfeature the uplink and downlink wireless communications on differentfrequency bands but divided as well in the time domain.

The very nature of the cellular network is that communications betweenthe UE and the RAN is asymmetrical in favor of the downlink wirelesslink. That is, more data is usually sent from the RAN to the UE thanfrom the UE to the RAN. In order to compensate for this, cell plannerswill often allocate more frequency or time resources (depending onwhether the network is FDD or TDD) to the downlink wirelesscommunications than are allocated to the uplink wireless communications.

This resource asymmetry creates problems for the UE in trying to managethe necessary HARQ acknowledgements because there are often insufficientuplink resources on the uplink control channels to transmit theseresponses. This problem is only exasperated with the addition ofmultiple carriers and other uplink signaling such as Channel StateInformation.

In LTE, wireless transmissions are typically broken into discrete unitscalled frames, which may then be broken down into sub-frames and thesub-frames into one or more code words. Each code word may have amapping relationship with a particular transport block and herein areused interchangeably unless specified otherwise. With FDD systems, theHARQ response may be transmitted at a fixed number of sub-frames afterthe transmission is received (typically 4 sub-frames later). However,with TDD systems, a fixed delay is not possible as there often are avariable number of uplink and downlink timeslots in a radio frame due tothe asymmetric wireless imbalance.

To solve these problems, for TDD systems, the 3^(rd) GenerationPartnership Project (3GPP) which promulgates the standards for 4G (LTE)wireless networks has developed several mechanisms. The first isACK/NACK/DTX time domain bundling. For HARQ-ACK bundling, the ACK, NACK,or DTX result for each particular code word in each downlink sub framefor a particular number of sub frames (called a bundling window)received on the downlink channel (e.g., a Physical Downlink SharedChannel—PDSCH) are logically AND'ed to produce one or multiple compositeresult corresponding to each code word in all the sub frames of abundling window. The number of composite ACK/NACK/DTX results producedthen equals the number of code words in a sub-frame. For example, if thesize of bundling window is four downlink sub-frames, and each sub-framehas two code words, the acknowledgements of the first code word ofsub-frames 0-3 are logically AND'ed together, and the second code wordsof sub-frames 0-3 are also AND'ed together to produce twoacknowledgement bits. The benefit of this technique is that it is verycompact, using few bits so that the uplink coverage can be assured. Thedownside is that if any one of the code words of any one of thesub-frames is not received correctly, then the particular code word forall sub-frames will be retransmitted. Another technique is to useHARQ-ACK multiplexing which may logically AND code words across the codewords (i.e. called spatial domain bundling) for each downlink sub-frameindividually to produce one acknowledgement bit per each down link subframe. The result is an ACK/NACK/DTX result for each associated downlinksub frame within a bundling window. For four down link sub-frames, withtwo code words per sub frame, a spatial domain bundling across two codewords (if any) by logical AND operation is applied in the sub-frame andthe multiple bundled ACK/NACKs in the sub-frames may result in onecomposite state within a bundling window. For a HARQ-ACK response senton the Physical Uplink Control Channels (PUCCH), the composite state maybe represented as a combination of a PUCCH resource and constellationpoints. This results in four acknowledgement results—one for eachsub-frame. Notice that despite the fact that the name for thisparticular HARQ-ACK technique is “multiplexing,” throughout thespecification the term “bundling window” is used.

A bundling window is a time unit (e.g., a number of sub-frames)specifying when HARQ-ACK feedback corresponding to down link traffic ata particular uplink sub frame is transmitted in the uplink. A UEtransmits HARQ-ACK feedback using the PUCCH in a sub-frame n where theHARQ-ACK feedback for n−k_(i), where k_(i)εK (defined in Table 1) and0≦i≦M−1. The bundling window is generally defined as the down linksub-frames of n−k_(i) for an uplink HARQ-ACK feedback at sub-frame n.

TABLE 1 Downlink association set index K: {k₀, k₁, . . . k_(M−1)} forTDD UL-DL Config- Subframe n uration 0 1 2 3 4 5 6 7 8 9 0 — — 6 — 4 — —6 — 4 1 — — 7, 6 4 — — — 7, 6 4 — 2 — — 8, 7, — — — — 8, 7, — — 4, 6 4,6 3 — — 7, 6, 11 6, 5 5, 4 — — — — — 4 — — 12, 8, 6, 5, — — — — — — 7,11 4, 7 5 — — 13, 12, 9, — — — — — — — 8, 7, 5, 4, 11, 6 6 — — 7 7 5 — —7 7 —TDD UL-DL configuration table is given as Table 2.

TABLE 2 TDD UL-DL configuration TDD Downlink UL/DL to Uplink Config-Switch Point Sub-frame number uration Periodicity 0 1 2 3 4 5 6 7 8 9 05 ms D S U U U D S U U U 1 5 ms D S U U D D S U U D 2 5 ms D S U D D D SU D D 3 10 ms  D S U U U D D D D D 4 10 ms  D S U U D D D D D D 5 10 ms D S U D D D D D D D 6 5 ms D S U U U D S U U D TDD Uplink/DownlinkConfigurations (D = downlink, S = special sub-frame with the threefields DwPTS, GP and UpPTS which is used to give the UE time to switchfrom downlink to uplink, U = uplink).

LTE Advanced supports carrier aggregation in which multiple carriers maybe utilized in the downlink. This means that multiple ACK/NACKinformation bits for multiple carriers need to be fed back in theuplink. For this, LTE defines a technique known as channel selectionwith time domain bundling. This technique utilizes a similar techniqueas the HARQ-ACK multiplexing except that time domain bundling of thistechnique is slightly different from the existing one. The time domainbundling for carrier aggregation may be for transmitting the number ofconsecutive ACKs for each component carrier while that for singlecarrier is for transmitting the logically bundled HARQ-ACK information.The resultant ACK/NACK information may be encoded by the joint selectionof a channel and a QPSK constellation symbol. Essentially, themultiplexed acknowledgement results may then be indexed into a lookuptable to select a two bit field (the QPSK constellation) and a PUCCHresource (the selected channel) for PUCCH transmission. A RM code inputbit set is also provided in case the HARQ-ACK is piggybacked on PUSCH.The mapping tables are shown in FIGS. 1, and 2 (FIG. 2 is continued onFIG. 2A) for different bundling window sizes. The column labeledHARQ-ACK(0)-(2) for FIG. 1 and HARQ-ACK(0)-(3) for FIG. 2 and FIG. 2Arepresent the ACK, NACK, or DTX decision for that particular sub-framefor both the primary and secondary cells (PCell and SCell respectively).For example, in the case of a four sub frame bundling window, ifsub-frame(0) was received successfully (ACK), sub-frame(1) was receivedunsuccessfully (NACK), sub-frame (2) was received successfully (ACK),and sub-frame (3) was received successfully (ACK) on the primary celland a response of ACK, ACK, ACK, NACK, on the secondary cell, the UEwould select a constellation of (0,1) with a feedback resourcecorresponding to a Physical Uplink Control Channel (PUCCH) 3 and usingcode input bits of 0,0,1,1. In short, the HARQ-ACK(j) column is theACK/NACK/ or DTX response for each particular downlink sub frame foreach of the primary and secondary cells (for multiple carriers) and thecorresponding PUCCH resources, constellations, and RM code input bits touse depending on the HARQ-ACK(j) selected for each of the primary andsecondary cells. This technique utilizes PUCCH format 1b when HARQ-ACKis transmitted using PUCCH.

HARQ-ACK bundling or HARQ-ACK multiplexing may not work properly if theUE does not correctly receive the scheduling information for anyscheduled frames. For example, if the eNodeB schedules the terminal fortwo sub-frames with a bundling window size 2, but the UE only receivedthe last frame, but was unaware that it was scheduled in the firstframe, the UE would reply with an ACK. The eNodeB would interpret thisACK as an acknowledgement of both sub-frames. In order to determine whena downlink grant for a UE is missed, the LTE specification provides aDownlink Assignment Index (DAI) sent to the UE from the RAN along withthe downlink scheduling information on the PDCCH. The DAI conveyed indownlink grant demotes the accumulative number of PDCCH(s) with assignedPDSCH transmission(s) and PDCCH indicating Semi Persistent Scheduling(SPS) release up to the present sub-frame within the same bundlingwindow of each configured serving cell. The UE then utilizes the DAI togenerate the HARQ-ACK(j) within the bundling window.

Turning now to FIG. 3, an example response calculation is shown. In theexample of FIG. 3, a bundling window of four sub-frames (M=4) is shownin two configured cells. The HARQ-ACK(j) response for the primary cell(PCell) is ACK, ACK, DTX, ACK and in the secondary cell (SCell) it isACK, NACK, NACK, ACK, respectively. The DAIs received on the PDCCH forthe PCell are 1 for sub-frame 0, 2 for sub-frame 1, and 4 for sub-frame3. Note that the UE was not able to decode the PDCCH on sub-frame 2(m=2) and thus did not update its DAI value. Even though the UE lost theupdated DAI value it recovers it in sub-frame m=3 and thus knows thatthe DAI is 4 at the end of the bundling window. Because the DAI value is4, the UE knows that it needs four HARQ-ACK(j) responses. For the SCell,the DAI's received on the PDCCH are 1, 2, 3, and 4 for sub-frames 0, 1,2, and 3 respectively.

Based on the mapping table in FIGS. 2 and 2A this produces a responseof:

Constel- RM Code Primary Cell Secondary Cell Resource lation Input BitsHARQ-ACK(0), HARQ-ACK(0), PUCCH b(0), o(0), o(1), HARQ-ACK(1),HARQ-ACK(1), RESOURCE b(1) o(2), o(3) HARQ-ACK(2), HARQ-ACK(2),HARQ-ACK(3) HARQ-ACK(3) ACK, ACK, (ACK, NACK/ 1 0, 1 1, 0, 0, 0NACK/DTX, DTX, any, any), any except for (ACK, DTX, DTX, DTX)Note that there is a problem when all sub-frames of a particularbundling window are not scheduled by the RAN. Since certain frames arenot scheduled, the DAI will not be incremented and will be less than thebundling window size at the end of the bundling window. The feedbacktables of FIG. 1 and FIG. 2 assume that all frames are scheduled. FIG. 4shows one example of this issue. In this example the first two downlinksub-frames in the PCell are not scheduled. Thus for sub-frame 2, DAI is1 and for sub-frame 3, DAI is 2 (compared to FIG. 3, where DAI was 3 and4 for sub frames 2 and 3 respectively). Since the HARQ-ACK (j) isdetermined in conjunction with the DAI value, HARQ-ACK(0) corresponds tosub-frame 2 and HARQ-ACK(1) corresponds to sub-frame 3. However,HARQ-ACK(2) and HARQ-ACK(3) are undefined because there are nocorresponding DAI values of 3 and 4 within the bundling window accordingto the definition of DAI. This is because the DAI value is defined asthe accumulative number of PDCCH(s) within an assigned PDSCHtransmission(s) and PDCCH indicating downlink Semi-Persistent Scheduling(SPS) release up to the present sub-frame within a bundling window.Therefore, if there is no expected DL sub-frame to be monitored by a UEfor HARQ-ACK(j) related to DAI value within a bundling window, a UEbehavior is not specified.

Disclosed in some examples are systems, methods, UEs, andmachine-readable media which solve the issue of generating anacknowledgement for the situation in which a last received DAI (LDAI)value is less than a size of a bundling window. In some examples, apredetermined state is utilized for HARQ-ACK(j) for the caseLDAI<=j<M−1, where M is the multiplexing or bundling window size. Forexample, the DTX state may be padded into these HARQ-ACK responses. Sofor example, in FIG. 4, the HARQ-ACK(j) for the PCell to use todetermine the proper response parameters would be: ACK, ACK, DTX, DTX.

Since the last two states for the PCell are padded by DTX, the UE willknow the exact mapping from the table to use. In addition, on thenetwork side, since the eNodeB already knows the last two states arepadded with DTX, the irrelevant states other than DTX can be excludedduring PUCCH detection hypothesis tests which may improve HARQ-ACKdetection performances. For example in FIG. 3, since the HARQ-ACKresponse in PCell is {ACK, ACK, DTX, DTX}, {ACK, NACK, DTX, DTX}, {NACK,ACK, DTX, DTX}, or {NACK, NACK, DTX, DTX}, the states of {any, any,ACK/NACK, ACK/NACK} can be excluded in eNB detection. By decreasing thedetection hypothesis tests, the PUCCH detection performance may beenhanced.

Applying this method to the example shown in FIG. 4 produces:

Constel- RM Code Primary Cell Secondary Cell Resource lation Input BitsHARQ-ACK(0), HARQ-ACK(0), PUCCH b(0), o(0), o(1), HARQ-ACK(1),HARQ-ACK(1), RESOURCE b(1) o(2), o(3) HARQ-ACK(2), HARQ-ACK(2),HARQ-ACK(3) HARQ-ACK(3) ACK, ACK, (ACK, NACK/ 1 0, 1 1, 0, 0, 0NACK/DTX, DTX, any, any), any except for (ACK, DTX, DTX, DTX)

While in some examples the HARQ-ACK(j) may be filled with DTX for thecase in which all downlink sub-frames within a bundling window were notscheduled, in other examples, other values may be used, such as an ACK,NACK, or another defined value. This is because the eNodeB has enoughsystem knowledge to ignore these values. In fact, in some examples, theUE may arbitrarily choose any ACK/NACK/DTX value.

Turning now to FIG. 5A, a method 5000 of acknowledging a transmissionwhen not all the downlink frames in a particular bundling window havebeen scheduled is shown. At operation 5010, the UE receives schedulinginformation on the PDCCH indicating downlink frames which are scheduled.At operation 5020, the UE determines that it has received the lastdownlink assignment for a particular bundling window and at operation5030 determines that the last DAI value (LDAI) is less than the bundlingwindow size. At operation 5040 the UE determines the ACK/NACK/DTXresponses for the frames for which the UE was aware it was scheduled. Atoperation 5050, the remaining HARQ-ACK(j) that do not have correspondingDAI values are filled in with a predetermined value (e.g., DTX).

Turning now to FIG. 5B, a method 5100 of processing an acknowledgementat an eNodeB of a transmission in which not all the downlink frames in aparticular bundling window have been scheduled is shown. At operation5110 the base station (e.g., an eNodeB) may schedule one or moredownlink transmissions for a particular acknowledgement period (e.g., abundling window) and notify the UE through a downlink control channelsuch as a Physical Downlink Control Channel (PDCCH). At operation 5120,the eNodeB may transmit the scheduled frames. At operation 5130 theeNodeB may receive the response from the UE. At operation 5140, theeNodeB may determine that the last DAI value sent on the PDCCH is lessthan a bundling window size. At operation 5150, the eNodeB may use theresource (e.g., the PUCCH resource) that the response was received onalong with the received constellation and RM code bits to determine theresponse, factoring in that the HARQ-ACK(j) where j is LDAI<=j<M−1,where M is the multiplexing or bundling window size, are padded values.The eNodeB may then transmit any necessary retransmissions.

Turning now to FIG. 6 a system 6000 for acknowledging transmissions isshown. User Equipment (UE) 6010 communicates with a Radio Access Network(RAN) 6020 which may include one or more base stations (e.g., an eNodeB)6030, 6035 over one or more radio links 6040. RAN 6020 may be connectedto a core network 6045, such as an enhanced Packet Core. EPC 6045 may beconnected to a network 6050, such as the internet, a Plain Old TelephoneService network (POTS), or the like. In the system of FIG. 6, the radiolinks 6040 may operate in a Time Division Duplex mode (TDD) mode.

FIG. 7 shows a partial functional diagram of a UE 7000 (more componentsnot shown may be included). UE 7000 may include a transmission module7010. The transmission module 7010 may transmit control and user trafficto the RAN over one or more uplink channels such as a Physical UplinkControl Channel (PUCCH), a Physical Uplink Shared Channel (PUSCH) or thelike. Transmission module 7010 may transmit the acknowledgements of usertraffic and control traffic sent from the RAN to the UE 7000 on thedownlink channels (e.g., the Physical Downlink Shared Channel(PDSCH)—and the Physical Dedicated Control Channel (PDCCH)).

Reception module 7020 may receive information sent by the RAN on thedownlink channels such as the Physical Downlink Shared Channel (PDSCH)and Physical Downlink Control Channel (PDCCH) and inform the responsemodule 7030 of the reception status of that information. For example,received sub-frames may be decoded at the reception module (and any FECcorrection may be done here as well) and an indication of whether thesub-frame should be ACK'ed, NACK'ed, or DTX'ed may be sent to theresponse module 7030. Reception module 7020 may also pass variouscommunication parameters to the response module 7030 such as the size ofthe bundling window and the last received DAI for that window.

Response module 7030 may inform the transmission module 7010 of theappropriate response parameters (e.g., PUCCH resource, RM code bits,constellation) according to the tables in FIG. 1 and FIG. 2 (continuedon FIG. 2A) based upon the LDAI, the bundling window size and the like.For example, the response module 7030 may make a determination that anumber of received downlink assignments is less than a response bundlingwindow size and based upon that determination, set the reception statusof each received downlink assignment based on whether a frame associatedwith the particular received downlink assignment was successfullyreceived and setting the reception status of a frame in the bundlingwindow that did not have a corresponding downlink assignment to apredetermined value. For example, the response module may determine foreach index j for a plurality of downlink sub-frames in a responsebundling window if one or more received downlink assignment index (DAI)values is equal to j+p. Determining a reception status (ACK/NACK/DTX) ofthe sub-frame corresponding to j responsive to determining that one ofthe one or more DAI values is equal to j+p. Setting the reception statusof the sub-frame corresponding to j to a predetermined value responsiveto determining that none of the one or more DAI values is equal to j+p.Where p is a constant (e.g., 0 or 1), where the one or more DAI valuesis received over the Physical Downlink Control Channel (PDCCH), wherej≦M−1, and where M is a number of sub-frames in a HARQ bundling window.The response module 7030 may also be called a HARQ module and may theninstruct the transmission module 7010 to transmit the appropriatelydetermined response. In some examples, the variable p may be equal tozero if there is a Physical Downlink Shared Channel (PDSCH) transmissionon the primary cell without a corresponding PDCCH detected within thebundling window, otherwise p may be one. Therefore, the value p canrepresent whether a semi-persistent scheduling (SPS) PDSCH without thecorresponding PDCCH exists within a bundling window or not. Note thatwhile the specification describes a PDCCH with a DAI value for ascheduled downlink frame, the disclosure may also be used when the UEreceives a PDCCH indicating a downlink Semi-Persistent Scheduling (SPS)release message which also includes a DAI value.

FIG. 7 also shows a partial functional diagram of an eNodeB 7100 (morecomponents not shown may be included). eNodeB 7100 includes atransmission module 7110 which transmits user data and control data onone or more channels. For example, user data or control data may betransmitted on a Physical Dedicated Control Channel (PDCCH) or aPhysical Dedicated Shared Channel (PDSCH). The transmission module 7110may schedule frames for transmission and signal the UE on the PDCCH. Thetransmission module 7110 may also transmit the DAI in the PDCCH. Thereception module 7120 may receive control and user data on the uplinkcommunication channels such as the Physical Uplink Control Channel(PUCCH) and the Physical Uplink Shared Channel (PUSCH). Reception module7120 may receive the HARQ responses from the UE to the downlinksub-frames (e.g., the ACK-NACK-DTX responses). In response to thisinformation, the reception module may indicate to the transmissionmodule that certain data may need to be retransmitted. The receptionmodule 7120 may decode the response based on determining which PUCCHresource the response was received upon, the received constellationbits, and the received RM codes. The reception module 7120 may alsodetermine that the last DAI value in the bundling window was less thanthe number of sub-frames in the bundling window and that one or more ofthe ACK/NACK/DTX of the sub-frames should be ignored as not representingan actual transmission.

FIG. 8 illustrates a block diagram of an example machine 8000 upon whichany one or more of the techniques (e.g., methodologies) discussed hereincan be performed. The UE, the RAN (including the eNodeBs) or the EPC maybe or include parts of, machine 8000. In alternative embodiments, themachine 8000 can operate as a standalone device or can be connected(e.g., networked) to other machines. In a networked deployment, themachine 8000 can operate in the capacity of a server machine, a clientmachine, or both in server-client network environments. In an example,the machine 8000 can act as a peer machine in peer-to-peer (P2P) (orother distributed) network environment. The machine 8000 can be apersonal computer (PC), a tablet PC, a set-top box (STB), a PersonalDigital Assistant (PDA), a mobile telephone (such as a UE), a webappliance, a wireless base station, a network router, switch or bridge,or any machine capable of executing instructions (sequential orotherwise) that specify actions to be taken by that machine. Further,while only a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein, such as cloudcomputing, software as a service (SaaS), other computer clusterconfigurations. For example, the functions of the machine 8000 can bedistributed across multiple other machines in a network.

Examples, as described herein, can include, or can operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities capable of performing specified operations and can beconfigured or arranged in a certain manner. In an example, circuits canbe arranged (e.g., internally or with respect to external entities suchas other circuits) in a specified manner as a module. In an example, thewhole or part of one or more computer systems (e.g., a standalone,client or server computer system) or one or more hardware processors canbe configured by firmware or software (e.g., instructions, anapplication portion, or an application) as a module that operates toperform specified operations. In an example, the software can reside (1)on a non-transitory machine-readable medium or (2) in a transmissionsignal. In an example, the software, when executed by the underlyinghardware of the module, causes the hardware to perform the specifiedoperations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor can beconfigured as one or more modules that can change over time. Softwarecan accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

Machine (e.g., computer system) 8000 can include a hardware processor8002 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 8004 and a static memory 8006, some or all of which cancommunicate with each other via a bus 8008. The machine 8000 can furtherinclude a display unit 8010, an alphanumeric input device 8012 (e.g., akeyboard), a user interface (UI) control device 8014, and/or other inputdevices. In an example, the display unit 8010 and UI control device 8014can be a touch screen display. The machine 8000 can additionally includea storage device (e.g., drive unit) 8016, a signal generation device8018 (e.g., a speaker), and a network interface device 8020.

The storage device 8016 can include a machine-readable medium 8022 onwhich is stored one or more sets of data structures or instructions 8024(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 8024 can alsoreside, completely or at least partially, within the main memory 8004,within static memory 8006, or within the hardware processor 8002 duringexecution thereof by the machine 8000. In an example, one or anycombination of the hardware processor 8002, the main memory 8004, thestatic memory 8006, or the storage device 8016 can constitute machinereadable media.

While the machine-readable medium 8022 is illustrated as a singlemedium, the term “machine readable medium” can include a single mediumor multiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) that configured to store the one or moreinstructions 8024.

The term “machine-readable medium” can include any tangible medium thatis capable of storing, encoding, or carrying instructions for executionby the machine 8000 and that cause the machine 8000 to perform any oneor more of the techniques of the present disclosure, or that is capableof storing, encoding or carrying data structures used by or associatedwith such instructions. Non-limiting machine-readable medium examplescan include solid-state memories, and optical and magnetic media.Specific examples of machine-readable media can include: non-volatilememory, such as semiconductor memory devices (e.g., ElectricallyProgrammable Read-Only Memory (EPROM), Electrically ErasableProgrammable Read-Only Memory (EEPROM)) and flash memory devices;magnetic disks, such as internal hard disks and removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 8024 can further be transmitted or received over acommunications network 8026 using a transmission medium via the networkinterface device 8020. Network interface device 8020 may connect themachine 8000 to a network of other machines in order to communicate withthe other machines in the network by utilizing any one of a number oftransfer protocols (e.g., frame relay, internet protocol (IP),transmission control protocol (TCP), user datagram protocol (UDP),hypertext transfer protocol (HTTP), etc.). Example communicationnetworks can include a local area network (LAN), a wide area network(WAN), a packet data network (e.g., the Internet), mobile telephonenetworks (e.g., cellular networks), Plain Old Telephone (POTS) networks,and wireless data networks (e.g., Institute of Electrical andElectronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®,IEEE 802.16 family of standards known as WiMax®), peer-to-peer (P2P)networks, among others. In an example, the network interface device 8020can include one or more physical jacks (e.g., Ethernet, coaxial, orphone jacks) or one or more antennas to connect to the communicationsnetwork 8026. In an example, and as shown in FIG. 8, the networkinterface device 8020 can include a plurality of antennas (not shown) towirelessly communicate using at least one of single-inputmultiple-output (SIMO), multiple-input multiple-output (MIMO), ormultiple-input single-output (MISO) techniques. The term “transmissionmedium” shall be taken to include any intangible medium that is capableof storing, encoding or carrying instructions for execution by themachine 8000, and includes digital or analog communications signals orother intangible medium to facilitate communication of such software.

OTHER NOTES AND EXAMPLES Example 1

Disclosed is a User Equipment (UE) comprising a response module arrangedto receive one or more downlink assignments of a bundling window over awireless downlink control channel; set a reception status for eachsub-frame of a downlink data channel in the bundling window based onwhether the sub-frame on the downlink data channel was associated with aparticular one of the downlink assignments and based upon whether thesub-frame was successfully received; and set a reception status ofsub-frames of the downlink data channel in the bundling window that didnot have a corresponding downlink assignment to a predetermined value;and a transmission module arranged to transmit a response, the responsebased upon the reception statuses set by the response module.

Example 2

The UE of example 1, wherein the reception status is one of:acknowledgement (ACK), negative acknowledgement (NACK), andDiscontinuous Reception (DRX).

Example 3

The UE of any one of examples 1-2, wherein the predetermined value is avalue indicating a discontinuous transmission (DTX).

Example 4

The UE of any one of examples 1-3, wherein the UE is arranged to operatein a Time Division Duplex (TDD) mode and wherein the transmission moduleis arranged to transmit the response using a Physical Uplink ControlChannel (PUCCH) format 1b.

Example 5

The UE of any one of examples 1-4, wherein the bundling window isgreater than 2 sub-frames.

Example 6

The UE of any one of examples 1-5, wherein the transmission module isarranged to transmit the response by selecting a PUCCH uplink resource,a constellation, and a set of code input bits based upon the receptionstatuses.

Example 7

The UE of any one of examples 1-6, wherein the UE is arranged tocommunicate with a wireless network using a Long Term Evolution (LTE)family of standards.

Example 8

The UE of any one of examples 1-7, wherein the UE is arranged to utilizecarrier aggregation with two serving cell configurations.

Example 9

Disclosed is a method comprising determining for each index j for aplurality of downlink sub-frames if one or more received downlinkassignment index (DAI) values are equal to j+p, the one or more DAIvalues received over a Physical Downlink Control Channel (PDCCH), wherej≦M−1, M being a number of sub-frames in a HARQ bundling window, whereinp is a constant; setting the reception status of the sub-framecorresponding to j to a predetermined value responsive to determiningthat none of the one or more DAI values is equal to j+1; andtransmitting the reception status of each of the plurality of downlinksub-frames j in the bundling window M.

Example 10

The method of example 9, wherein the predetermined value is a valueindicating a discontinuous transmission (DTX).

Example 11

The method of any one of examples 9-10, comprising: determining if thereis a Primary Downlink Shared Channel (PDSCH) transmission on a primarycell without a corresponding PDCCH detected within the bundling window;responsive to determining that there is a PDSCH without a correspondingPDCCH, setting p to 0; responsive to determining that there are no PDSCHwithout a corresponding PDCCH, setting p to 1.

Example 12

The method of any one of examples 9-11, wherein the reception statusesare transmitted using a Physical Uplink Control Channel (PUCCH) format1b.

Example 13

The method of any one of examples 9-12, comprising transmit thereception statuses by at least selecting a PUCCH uplink resource, aconstellation, and a set of code input bits based upon the receptionstatuses.

Example 14

Disclosed is a User Equipment (UE) comprising: a Hybrid Automatic RepeatRequest (HARQ) module arranged to: for each index j for a plurality ofdownlink sub-frames: determine if one or more received downlinkassignment index (DAI) values is equal to j+p, where p is a constant,the one or more DAI values received over a Physical Downlink ControlChannel (PDCCH), where j≦M−1, and where M is a number of sub-frames in aHARQ bundling window, determine a reception status of the sub-framecorresponding to j responsive to determining that one of the one or moreDAI values is equal to j+p, and setting the reception status of thesub-frame corresponding to j to a predetermined value responsive todetermining that none of the one or more DAI values is equal to j+p; anda transmission module arranged to transmit the reception status of eachof the plurality of downlink sub-frames j in the bundling window M.

Example 15

The UE of example 14, wherein the reception status is one of:acknowledgement (ACK), negative acknowledgement (NACK), andDiscontinuous Reception (DTX).

Example 16

The UE of any one of examples 14-15, wherein the predetermined value isa value indicating a discontinuous transmission (DTX).

Example 17

The UE of any one of examples 14-16, wherein the predetermined value isa value different from a value indicating an ACK, a NACK, and a DTX.

Example 18

The UE of any one of examples 14-17, wherein the predetermined value isa value chosen at random from one of a value indicating an ACK, a NACK,and a DTX.

Example 19

The UE of any one of examples 14-18, wherein the UE is arranged tooperate in a Time Division Duplex (TDD) mode.

Example 20

The UE of any one of examples 14-19, wherein the UE is arranged tomultiplex HARQ reception statuses.

Example 21

The UE of any one of examples 14-20, wherein the transmission module isarranged to transmit the reception statuses using a Physical UplinkControl Channel (PUCCH) format 1b.

Example 22

The UE of any one of examples 14-21, wherein the HARQ module is furtherarranged to: determine if there is a Primary Downlink Shared Channel(PDSCH) transmission on a primary cell without a corresponding PDCCHdetected within the bundling window; responsive to determining thatthere is a PDSCH without a corresponding PDCCH, setting p to 0;responsive to determining that there are no PDSCH without acorresponding PDCCH, setting p to 1.

Example 23

The UE of any one of examples 14-22, wherein the transmission module isarranged to transmit the reception status by selecting a PUCCH uplinkresource, a constellation, and a set of code input bits based upon thereception statuses.

Example 24

The UE of any one of examples 14-23, wherein the UE is arranged tocommunicate with a wireless network using a Long Term Evolution (LTE)family of standards.

What is claimed is:
 1. A User Equipment (UE) comprising: HybridAutomatic Repeat Request (HARQ) circuitry arranged to: determine that adownlink assignment index (DAI) is not equal to j+p, where p is aconstant and j is the index of a downlink subframe; and transmissioncircuitry arranged to: transmit a HARQ reception status of DiscontinuousReception responsive to the determination.
 2. The UE of claim 1, furthercomprising receiver circuitry, and wherein the receiver circuitry isarranged to receive the DAT in the downlink subframe.
 3. The UE of claim2, wherein the receiver circuitry is further configured to: receive theDAI over a Physical Downlink Control Channel (PDCCH).
 4. The UE of claim3, wherein the receiver circuitry is further configured to: receive theDAI in a downlink Semi-Persistent Scheduling (SPS) release message overthe PDCCH.
 5. The UE of claim 4, wherein the transmission circuitry isconfigured to transmit the HARQ reception status responsive to receivingthe SPS release message.
 6. A non-transitory computer-readable mediumcomprising instructions that, when executed on a device, cause thedevice to: determine that a downlink assignment index (DAI) is not equalto j+p, where p is a constant and j is the index of a downlink subframe;and transmission circuitry arranged to transmit a HARQ reception statusof Discontinuous Reception responsive to the determination.
 7. Thenon-transitory computer-readable medium of claim 6, comprisinginstructions to further cause the device to receive the DAI in thedownlink subframe.
 8. The non-transitory computer-readable medium ofclaim 7, comprising instructions to further cause the device to receivethe DAT over a Physical Downlink Control Channel (PDCCH).
 9. Thenon-transitory computer-readable medium of claim 8, comprisinginstructions to further cause the machine to receive the DAI in adownlink Semi-Persistent Scheduling (SPS) release message over thePDCCH.
 10. The non-transitory computer readable medium of claim 9,comprising instructions to further cause the machine to transmit theHARQ reception status responsive to receiving the SPS release message.11. An evolved NodeB (eNodeB) comprising: a transmission module arrangedto transmit a downlink sub-frame having an index value of j; and areception module arranged to receive a HARQ reception status ofDiscontinuous Reception (DTX) responsive to transmitting the downlinksub-frame with a value for a downlink assignment index (DAI) that is notequal j+p where p is a constant.
 12. The eNodeB of claim 11, etransmission module transmits the DM over a PDCCH.
 13. The eNodeB ofclaim 12, wherein the transmission module transmits the DM in a downlinkSemi-Persistent Scheduling (SPS) release message over the PDCCH.
 14. TheeNodeB of claim 11, wherein the eNodeB is arranged to operate in a TimeDivision Duplex (TDD) mode.
 15. The eNodeB of claim 11, wherein thereception module is arranged to receive multiplexed HARQ receptionstatuses for a plurality of downlink sub-frames, the plurality ofdownlink sub-frames comprising a bundling window of M downlinksub-frames.
 16. A non-transitory computer-readable medium comprisinginstructions that, when executed on a device, cause the device to:transmit a downlink sub-frame having an index value of j; and receive aHARQ reception status of Discontinuous Reception (DTX) responsive totransmitting the downlink sub-frame with a value for a downlinkassignment index (DM) that is not equal to j+p where p is a constant.17. The non-transitory computer-readable medium of claim 16, comprisinginstructions that further cause the device to: transmit the DAI over aPDCCH.
 18. The non-transitory computer-readable medium of claim 17,comprising instructions that further cause the device to: transmit theDAT in a downlink Semi-Persistent Scheduling (SPS) release message overthe PDCCH.
 19. The non-transitory computer-readable medium of claim 16,wherein the device is arranged to operate in a Time Division Duplex(TDD) mode.
 20. The non-transitory computer-readable medium of claim 16,wherein instructions further cause the device to: receive multiplexedHARQ reception statuses for a plurality of downlink sub-frames, theplurality of downlink sub-frames comprising a bundling window of Mdownlink sub-frames.